Summary:

A dendrometry study was conducted at the logged forest tower
site, km 83 site, Tapajos National Forest,
Para, Brazil over a period of 4 years following the implementation of a
reduced impact logging management regime. Dendrometer bands were installed to measure diameter
growth increments for 234 trees in an 18 ha plot adjacent to the eddy flux tower at the km 83 site. In addition to trees randomly
selected for measurements within the plot prior to logging, a set of
smaller diameter trees within or adjacent to gaps created during the
logging treatment were added to the study in 2002. Selective logging is a major land use in the
Amazon
Basin. An accurate accounting of the effect of logging on regional
carbon balances requires better information on the rates at which the
logged forest recovers biomass. There is one comma-delimited data file with this data set.

Figure 1. Dendrometer bands on trees at the km 83 study site.

Figure 2. The 18 ha intensive study plot at the km 83 site.
Trees equipped with dendrometer bands
before logging in November 2000 are shown as solid
points. Gaps created by selective logging in
September 2001 are shown as irregular shapes. The plot
has 25 N-S transects (numbered 0 to 24) and
13 E-W transects (lettered A to M). The 65 m flux tower is indicated
in block G4
(Figueira, et al., 2008).

Implementation of the LBA Data and Publication Policy by Data
Users:

The LBA Data and Publication Policy [http://daac.ornl.gov/LBA/lba_data_policy.html]
is in effect for a period of five (5) years from the date of archiving
and should be followed by data users who have obtained LBA data sets
from the ORNL DAAC. Users who download LBA data in the five years after
data have been archived must contact the investigators who collected
the data, per provisions 6 and 7 in the Policy.

This data set was archived in
January of 2011.
Users who download the data between January 2011 and December 2015 must
comply with the LBA Data and Publication Policy.

Data users should use the Investigator
contact
information in this document to communicate with the data provider.
Alternatively, the LBA Web Site [http://lba.inpa.gov.br/lba/]
in Brazil will have current contact information.

Data users should use the Data Set Citation
and other
applicable references provided in this document to acknowledge use of
the data.

Selective logging is a major land use in the
Amazon
Basin. An accurate accounting of the effect of logging on regional
carbon balances requires better information on the rates at which the
logged forest recovers biomass. Some data are available at fairly coarse
temporal scales on biomass responses to logging, but there remains a
need for a more mechanistic understanding of the response of tropical
forests to logging. In this study we installed dendrometer bands to
measure diameter growth increments for 234 trees in an 18 ha plot adjacent to the eddy flux tower at km 83,
Tapajos National Forest, Para, Brazil over a period of 4 years
following the implementation of a reduced impact logging management
regime. In addition to trees randomly selected for measurements within
the plot prior to logging, a set of smaller diameter trees with or
adjacent to gaps created during the logging treatment were added to the
study in 2002.

3. Data Application and Derivation:

The data collected as part of this data set, increments of
diameter, can be used to estimate annual rates of above ground biomass productivity
(Keller et al. 2001). Biometric measurements of productivity before and after logging can be compared to modeled results
to refine our predictions of carbon dynamics in tropical forests under logging management.

4. Quality Assessment:

We filtered the dendrometer data for the
highest quality,
most continuous data. Data from trees that died during the course of
the study or were removed by logging or trees where the dendrometer
itself was damaged and needed to be replaced during the study were
excluded from the final data presented here.

Users may note that diameter
measurements for
Block: L05 / Common name: cocao / Tree_tag: 249
shows a somewhat erratic pattern of increases and decreases. These
measurements were checked against the log books and verified as actual
measurements and therefore were not removed from the data file.

5. Data Acquisition Materials and Methods:

This work was done at the Tapajos National
Forest (TNF),
a 6,000,000 ha conservation area of of humid tropical forest with a mean
canopy height of 40 m. The study site is located 50 km south of
Santarem, Para via an access road at km 83 of the Santarem-Cuiaba
Highway. Mean annual precipitation of 1,911 mm has been recorded at a
weather station in Belterra, Para 50 km from the study sites (INEMET
1992), with a dry season extending from August through November.

Our 18 ha study site was located adjacent to the eddy flux
tower installed by the LBA-ECO Project and lay within a 3,200 ha reduced impact
logging demonstration management area. The 700 ha logging area at km 83 was
logged in three phases from August to December 2001, though most of the
disturbance in the 18 ha study area occurred in September 2001. Reduced
impact logging removed on average 2-3 trees per hectare with additional
damage associated with landings and skid trails.

From the trees included in the biomass
survey conducted
in March 2000, (Menton et al., 2011), 390 individuals were randomly selected and fitted with dendrometer bands (Liming 1957). Dendrometers were installed on trees
with diameters > 35 cm in November 2000, and on trees with
diameters
between 10 and 35 cm in February 2001. Additional dendrometers were
installed on small trees located within or near newly created logging
gaps in February 2002. At the installation of the dendrometers,
diameter was assumed to be the same as was measured in the original
biomass survey of March 2000. Change in tree circumference was measured
at 6-week intervals from November 2000 through November 2004 using
digital calipers. Change in circumference was converted to DBH
(diameter at breast height) increment in centimeters and recorded.

6. Data Access:

Data are available through the Oak Ridge
National
Laboratory (ORNL) Distributed Active Archive Center (DAAC).